The invention relates to computer aided design systems and methods.
Traditionally, computer aided design tools and the associated design libraries reside on a user""s computer system, either a workstation or personal computer, or a local (nearby) computer mainframe or fileserver at the user""s location or within the user""s local computer system. A sophisticated user-machine interface then permits the user to enter data into the CAD tool to enable that tool to process and display results, error messages, and so on to the user. If the user concerned is not the person responsible for maintaining the computer aided design tool (for example where the user concerned is not at the location where the CAD tool is created and maintained), it is necessary for the user to receive the CAD tool executables and libraries and to maintain his local copy. In a rapidly changing environment, frequent changes to the CAD tool may become necessary. FIG. 1 of the accompanying drawings is a schematic representation of this scenario where the CAD tools maintenance location 12 has to send copies of the relevant tools 14 (by physical or electronic means, as appropriate), to the relevant user CAD locations 16.
The disadvantages of this conventional approach of keeping local CAD tools can be summarised as follows:
1. CAD tool executables change frequently and the user must keep updating his local copy.
2. In turn, this means that the designers/maintainers of a CAD tool must send out multiple copies once a significant update has been made to the CAD tool concerned.
3. Libraries referred to by the executable are also changed frequency. Accordingly, the user must continue to update his local copies and the designers/maintainers of the CAD tool libraries must continue to send out multiple copies once significant updates have been made.
4. CAD designers/maintainers are reluctant to send out updates following minor tool or library updates due to the logistical overheads involved as indicated above. Accordingly, a user""s local CAD tool and associated library can rapidly get out of date.
5. File storage must be available for the CAD tool executables and associated library at the user""s location. Some CAD executables and libraries are used infrequently, but will nevertheless have to be backed up and maintained as any other piece of software at the user""s location.
6. The local computer power made available to the user must exceed the maximum requirements for acceptable performance during the execution of the CAD tool, which can significantly increase the cost of a user""s computing requirements.
Accordingly, it is an aim of the present invention to provide a solution which at least mitigates the various problems and disadvantages of the conventional CAD approach set out above.
In accordance with an aspect of the invention, there is provided a distributed computer aided design system comprising:
a computer aided design server station including a computer aided design tool for performing computer aided design tasks and a communications interface; and
one or more computer aided design client stations remote from the server station and connectable to the server station via a communications medium, a client station comprising display and data entry means for displaying a design parameter entry document to a user and for accepting design parameters entered by the user and a communications interface for transmitting the design parameters via the communications medium to the server station;
the computer aided design tool at the server station being configured to receive the design parameters from the client station, to perform computer aided design tasks based on the design parameters and to return a design task product to the server station via the communications medium. The design task product can comprise, for example, a file comprising parameters specifying a resulting design, for example, of a circuit for an integrated circuit.
An embodiment of the invention can provide significant advantages over the conventional CAD approach described earlier:
1. No local copy of the CAD tool executable needs to be kept on the user""s system. Accordingly, whenever the CAD tool executable is changed by the CAD designers/maintainers, only the master copy on the server station needs to be updated.
2. Updates are consequently only necessary at the server station and the need for distributing multiple copies is no longer required.
3. The same benefits as indicated at 1 and 2 also apply to CAD tool libraries.
4. CAD designers/maintainers will be encouraged to update the master copy much more regularly in view of the reduced logistics in this process.
5. The file storage for the CAD tool executables and libraries is only necessary at the server station, and only the master copy of this needs to be backed up. Users are therefore relieved of the requirement to maintain the CAD tool executables and libraries.
6. A consequence of the above is that only the server station needs to be provided with the computing power for providing acceptable performance during execution of the CAD tool. Preferably, this is able to handle multiple users, possibly in a batch, or alternatively in a coprocessing manner.
In a preferred embodiment of the invention, the communications medium is an intranet or internet medium. In such an embodiment a cost effective implementation of a client station is in the form of a computer workstation having web browser capability.
The client station can be arranged to generate its own parameter entry forms. However, it is advantageous for the server station to be configured to respond to a request communicated from a client station to supply a design parameter input form to the client station. This ensures that the parameter input form used; takes account of all input parameter requirements of the design tool concerned.
A preferred embodiment of the invention provides integrated circuit design functions. In this case, the computer aided design tool comprises circuit design executables and circuit design libraries, the circuit design executables being responsive to the design parameters to access the circuit design libraries automatically to perform the circuit design. A specific example of this which is particularly suitable for parameterised design specification provides memory design executables and memory design, libraries.
The computer aided design tool can also provide simulation tools.
The invention also provides a computer aided design server station for a distributed computer aided design system as set out above, the server station comprising a computer aided design tool for performing computer aided design task and a communications interface whereby the server station is connectable to at least one computer aided design client station remote from the server station via a communications medium, the computer aided design tool at the server station being configured to receive design parameters from a client station via the communications medium, to perform computer aided design tasks based on the design parameters and to return a design task product to the server station via the communications medium.
The invention further provides a method of conducting computer aided design at a client station for a distributed computer aided design system as set out above, the method comprising, at said client station, displaying a design parameter entry document to a user, accepting design parameters entered by the user, transmitting the design parameters via the communications medium to a remote computer aided design server station for performing computer aided design tasks on the design parameters, and receiving a design task product via the communications medium from the server station.
In accordance with another aspect of the invention, there is provided a method of performing computer aided design comprising steps of:
a) presenting a design parameter document to a user at a client computer aided design station;
b) following input of the computer aided design parameters, transmitting the computer aided design parameters via a communications medium to a remote computer aided design server station including a computer aided design tool for performing computer aided design tasks;
c) automatically performing computer aided design tasks in response to the design parameters; and
d) transmitting a design task product to the server station via the communications medium.